Boilers and steam generators are used to produce steam for heating process streams, for providing energy to do work, or simply to transfer energy to a desired location. While the heat exchange occurs, the steam is condensed into liquid and then typically recycled to the boiler. However, the condensate can sometimes contain corrosion products from the pipes as well as volatile organic compounds from treatment chemicals or natural organic compounds from a makeup water source. All of these contaminants affect the boiler performance and limit the number of cycles of concentration, and, thus, overall boiler efficiency. Therefore, purification of the condensate to remove corrosion products and organic compounds is sometimes desired, which can improve efficiency of the boiler system.
In addition to condensate, typical boiler operation includes blowdown that typically creates a waste stream having both water and energy value that can be recovered to further improve the efficiency and sustainability of the boiler system.
Several other water-containing industrial processes produce energy-rich water-containing streams that can be recovered similar to boiler condensate or blowdown. Non-limiting examples of these industrial processes may include food, dairy, beverage, landfill leachate, and biofuel processing.
By minimizing discharge of contaminated (a.k.a. “dirty”) streams such as poor quality condensate and blowdown, an operator can reduce cost and possibly even generate more total steam. In addition, condensate and blowdown have latent heat content that can be saved or re-used by the boiler system, thus reducing the amount of fuel needed to generate steam.